The Baghdad church siege which left 58 people dead horrified Iraq’s Christian community, hundreds of whom gathered on Tuesday for a memorial service in Baghdad.

The ISI said in an Internet statement its action was justified as a deadline expired for Egypt's Coptic church to free women allegedly held after converting to Islam.

The release of the women in Egypt was one of the militants’ demands during Sunday night’s siege, with the release of al Qaida-linked prisoners held in Iraq.

“We will open upon them the doors of destruction and rivers of blood”

“We will open upon them the doors of destruction and rivers of blood,” the insurgent group said in a statement posted on militant websites."Let these idolaters, and at their forefront, ...., know that the killing sword will not be lifted from the necks of their followers until they declare their innocence from what … the Egyptian Church is doing," the ISI said in its latest statement.

It also demanded that the Christians "show to the mujahedeen their seriousness to pressure this belligerent church to release the captive women from the prisons of their monasteries."

The women are the wives of Coptic priests whom Islamists have said were forcibly detained by the Coptic Church after they had willingly converted to Islam.

Footnote:While Christians were the target on Sunday in Baghdad, it was Shi’ites who bore the brunt of thirteen attacks on Tuesday that struck across the capital. In addition to 76 dead, 232 people were wounded, according to police and hospital officials who spoke on condition of anonymity.Fearing retribution for the attack, police on loudspeakers told people in the Sunni neighborhood of Azamiyah to stay home. In Sadr City, police ordered people to go home.The surge in violence is raising fresh concerns about the planned pullout of American troops next year.